Grimes Changes Her and Elon Musk's Daughter Exa Dark Sideræl's Name

Grimes just announce that her 1-year-old daughter with Elon Musk has a different, preferred name. The singer and billionaire previously named their daughter Exa Dark Sideræl Musk, but on Thursday Grimes tweeted that Exa goes by "'Y' now, or 'Why?' or just '?'" She explained that her daughter is named for "curiosity, the eternal question... and such."

Grimes and Musk have always managed to make headline news when it comes to naming their children, starting with their son X Æ A-12 born in 2020. His name had to be legally changed to X Æ A-Xii due to California state law, and according to Grimes it is pronounced "Ex Ash A Twelve" or "Ex Ay Eye." They were more circumspect with their second child, Exa, born in September of 2021 via surrogate. Grimes referred to the nickname "Y" in interviews as far back as July of 2022, describing it as a compliment to their son's name, X.

In an interview with Vanity Fair, Grimes said that the name Exa was meant to be a reference to the computer science term "exaFLOPS," which describes a supercomputer's ability to "perform 1 quintillion floating-point operations per second." The name Dark is meant to represent "the unknown," much like the nickname Y. Finally, Sideræl is a stylized spelling of the word "sidereal," which Grimes said is "the true time of the universe, star time, deep space-time, not our relative earth time." With its unique spelling, Grimes hoped it would evoke her favorite Lord of the Rings character, the elf Galadriel.

Grimes is a 35-year-old Canadian singer-songwriter whose real name is Claire Elise Boucher. She began her relationship with Musk in 2018 and it has been baffling to onlookers from day one. Musk, 51, had already been divorced three times and had seven children before getting involved with Grimes. Based on Grimes' music, they assumed her politics and perspective would be antithetical to Musk's.

The couple announced that they had "semi-separated" in September of 2021, and in January 2022 Grimes elaborated: "I would probably refer to him as my boyfriend, but we're very fluid." However, in March of 2022, she wrote on Twitter that they had broken up for real this time, adding: "he's my best friend and the love of my life." It's unclear how they are managing the co-parenting of X and Y.